A conventional electronic system (for example a server) is usually equipped with a fan module for dissipating heat generated from inner circuit components (for example central processing unit) using wind power to thereby prevent the inner circuit components from failure by being overheated.
FIG. 1 shows a schematic cross-sectional view of a conventional fan module 100 assembled to a server framework 10. As shown in FIG. 1, the conventional fan module 100 comprises an outer frame 110 and a fan unit 120, wherein the outer frame 110 in cross-section is substantially square-shaped, and a cylinder-shaped fan accommodating space 111 is formed in the outer frame 110 for accommodating the fan unit 120.
As shown in FIG. 1, in a practical embodiment, a height of a space provided by the server framework 10 for accommodating the fan module 100 is about 40.5 mm, a length of a side of the square-shaped outer frame 110 in cross-section is about 40 mm, and a diameter of the cylinder-shaped fan accommodating space 111 is about 38 mm, such that the maximum length of a fan of the fan unit 120 can only be 19 mm, and a distance between a top surface 110a or bottom surface 110b of the outer frame 110 of the fan module 100 and the server framework 10 is only 0.25 mm.
In practical implementation, the foregoing fan module 100 causes a drawback that since the distance between the top surface 110a or bottom surface 110b of the outer frame 110 and the server framework 10 is only 0.25 mm, this fails to provide a sufficient bump-preventing buffer space between the fan module 100 and the server framework 10 such that the fan module 100 is apt to bump against the server framework 10 due to up and down vibration generated in practical operation. This may cause internal vibration of the server and affect operation of internal delicate components of the server.
A solution to the above problem is to shorten the fan length of the fan unit 120 of the fan module 100, such that the side of the square cross-section of the outer frame 110 can be reduced in length to increase the distance between the top surface 110a or bottom surface 110b of the outer frame 110 and the server framework 10, thereby enlarging the bump-preventing buffer space. However, such method would undesirably degrade a heat dissipating effect provided by the fan module 100.
Another solution to the above problem is to reduce the thickness of the top surface 110a and the bottom surface 110b of the fan module 100, so as to reduce the height of the cross-section of the outer frame 110 and increase the distance between the top surface 110a or bottom surface 110b of the outer frame 110 and the server framework 10. However, such method would undesirably reduce the structural strength of the outer frame 110, making the fan module apt to be damaged by an external force.